powerpc: Move CONFIG_SYS_DDR_SIZE to CONFIG_SYS_SDRAM_SIZE

We have a number of CONFIG_SYS_xxx_SIZE options to describe the amount
main memory available.  Rework CONFIG_SYS_DDR_SIZE, which described a
size in number of MiB to use CONFIG_SYS_SDRAM_SIZE which is most often
used as a number of bytes.  Use shifts of this option when required.

Signed-off-by: Tom Rini <trini@konsulko.com>
7 files changed